Chemically curable liquid polyene-polythiol polymer composition

ABSTRACT

THE INVENTION DISCLOSED IS FOR A NEW CHEMICALLY CURABLE LIQUID POLYMER COMPOSITION WHICH INCLUDES A LIQUID POLYENE COMPONENT HAVING A MOLECULE CONTAINING AT LEAST TWO UNSATURATED CARBON-TO-CARBON BONDS DISPOSED AT TERMINAL POSITIONS ON A MAIN CHAIN BACKBONE OF THE MOLECULE, AND A POLYTHIOL COMPONENT HAVING A MOLECULE CONTAINING A MULTIPLICITY OF PENDANT OR TERMINALLY POSITIONED -SH FUNCTIONAL GROUPS PER AVERAGE MOLECULE. THE CHEMICALLY CURABLE LIQUID POLYMER COMPOSITION UPON CURING IN THE PRESENCE OF A CHEMICAL FREE RADICAL GENERATING REAGENT FORMS ODORLESS, SOLID, ELSTOMERIC PRODUCTS WHICH MAY SERVE AS SEALANTS, COATING, ADHESIVES, AND MOLDED ARTICLES.

United States Patent Office Patented Jan. 30, 1973 3,714,290 CHEMICALLYCURABLE LIQUID POLYENE- POLYTHIOL POLYMER COMPOSITION Clifton L. Kehr,Silver Spring, and Walter R. Wszolek, Sykesville, Md., assignors to W.R. Grace & Co., New York, N.Y.

No Drawing. Application June 23, 1970, Ser. No. 49,207,

which is a continuation-in-part of abandoned application Ser. No.617,801, Feb. 23, 1967, which in turn is a continuation-impart ofabandoned application Ser. No. 567,841, July 26, 1966. Divided and thisapplication June 25, 1971, Ser. No. 156,968

Int. Cl. C08d 1/00; C08f 1/16; C08c 11/54 US. Cl. 260-858 14 ClaimsABSTRACT OF THE DISCLOSURE The invention disclosed is for a newchemically curable liquid polymer composition which includes a liquidpolyene component having a molecule containing at least two unsaturatedcarbon-to-carbon bonds disposed at terminal positions on a main chainbackbone of the molecule, and a polythiol component having a moleculecontaining a multiplicity of pendant or terminally positioned --SHfunctional groups per average molecule. The chemically curable liquidpolymer composition upon curing in the presence of a chemical freeradical generating reagent forms odorless, solid, elastomeric productswhich may serve as sealants, coatings, adhesives, and molded articles.

The present application for US. Letters Patent is a divisional of Ser.No. 49,207, filed June 23, 1970, now Patent No. 3,662,023 issued on May9, 1972, which in turn isa continuation-in-part of copending applicationSer. No. 617,801, filed Feb. 23, 1967, now abandoned, which in turn is acontinuation-in-part of application Ser. No. 567,841, filed July 26,1966, now abandoned.

This invention relates to a new high energy curable liquid compositionwhich includes a liquid polyene component having a molecule containingat least two unsaturated carbon-to-carbon bonds disposed at terminalpositions on a main chain of the molecule, a polythiol component havinga molecule containing a multiplicity of pendant or terminally positionedSH functional groups per average molecule, and a photo-curing rateaccelerator.

It is well known in the art that cure of internally unsaturated polymerssuch as polybutadiene or polyisoprene may be effected with polythiols.However, such polymers, due mainly to residual internal unsaturationafter curing, are unstable either to thermal oxidation or ultra-violetcatalyzed oxidation, and are subject to rapid attack by ozone.Eventually degradation and embrittlement results in the internal doublebond polymers, substantially reducing their useful service life.

A limitation of commercially available liquid polyurethane prepolymersis the fact that they are terminated by isocyanate (NCO) groups. These--NCO groups are extremely unstable in storage, and are highlywater-sensitive such that under practical conditions, they react withtraces of moisture from the atmosphere to form gaseous carbon dioxideand amino groupings which in turn react with more NCO to form eventuallya highly viscous, sometimes completely insoluble urea-extended chainnetwork. In cases where insolubilization occurs, the polymer has to bediscarded at great expense. Further, if the -NCO-terrninated prepolymerscome in contact with traces of either acidic or basic impurities,dimerization and/or trimerization of the NCO functions may take place toform viscous, sometimes insoluble products during storage. Even mildalkalis such as those constituents normally present on the surface ofglass vessels and containers may cause storage problems.

A further limitation for some applications is found in polyurethanepolymers of the prior art which are derived from aromatic diisocyanatesor polyisocyanates such as tolylene-2,4-diisocyanate,tolylene-2,6-diisocyanate, 4,4- diisocyanatodiphenylmethane, and thelike. These aromatic diisocyanates (or mixtures thereof) enjoywidespread use in polyurethane elastomers, foams, and coatings, becauseof their ready commercial availability, high degree of reactivity andrelatively low cost. The derived polyurethane products, however, areknown to turn yellow, amber, orange or brown in color when exposed tosunlight, ultraviolet light or other forms of actinic radiation. Thisyellowing tendency imparts a definite limitation on the usage of suchpolyurethanes in many applications. There is evidence in the technicalliterature that shows that this yellowing or discoloration problem isdirectly attributable to the aromatic (benzenoid) nucleus in thearomatic diisocyanates, and accordingly serious yellowing problems inpolyurethanes may be avoided by use of aliphatic polyisocyanates such ashexamethylene diisocyanate. These aliphatic polyisocyanates, however,are difficult to manufacture, are relatively expensive and arerelatively slow in reaction rate during polymer formation reactions incomparison to the aromatic polyisocyanates.

The use of polymeric liquid polythiol polymers which are cured to solidelastomeric products by oxidative coupling of the thiol (SH) groups todisulfides (S-S- groups) are known in the sealants, coatings andadhesives field. Oxidizing agents such as Pb0 are commonly used toelfect this curing reaction. These mercapto-containing compounds,however, both before and after curing with PbO -type curing system yieldelastomeric compositions with an ottensive odor which limits theirusefulness generally to outdoor service. Thus, oxidatively-curedmercapto polymer systems have found restricted commercial acceptance dueto their olfensive odors.

A limitation of commercial liquid polymeric sealants and coatings isfound in one-package systems. All the compounding ingredients, includingthe curing agents, are blended together and charged into a tightlysealed container until used. In these commercial sealants (polysulfides,polydisulfides, polymercaptans, polyurethanes and polysilicones), thecuring reaction of one-package systems is initiated by moisture (H O)from the air. The moisturecurable systems leavesomething to be desiredbecause the moisture content of the air varies widely. Hence, the curingperformanceiot moisture-curable adhesives, coatings and sealants isvariable and is ditlicult to predict and control. In the case ofpolyurethanes a further disadvantage of moisture-curable systems isobserved. In the curing reaction (NCO groups reacting with H O), avolatile gas (carbon dioxide) is liberated and this evolved gas tends tocause unsightly and property-weakening gas pockets or voids in the finalproduct.

It has now been found that numerous defects of the prior art may beeffectively overcome by practice of the present invention which providesa new chemically curable liquid composition which contains particularpolyenes which are curable with polythiols to solid resins orelastomers. For example, when urethane-containing polyenes arecompounded with polythiols, the prepared composition may be storedsafely for long periods of time in the absence of a chemical freeradical generating reagent. Upon exposure to a chemical free radicalgenerating reagent, the system cures rapidly and controllably to apolythioether-polyurethane product which is low in cost and equal orbetter in reaction rate in polymer formation when compared withcompositions derived from conventional technology.

Generally stated, the present invention provides a curable compositionwhich comprises a particular polyene component, a polythiol component,and, a chemical free radical generating reagent.

The polyene component may be represented by the formula:

wherein m is an integer of at least 2 ,wherein X is a member selectedfrom the group consisting of:

In the groups (a) to (e), f is an integer from 1 to 9; R is a radicalselected from the group consisting of hydrogen, fluorine, chlorine,afuryl, thienyl, pyridyl, phenyl and substituted phenyl, benzyl andsubstituted benzyl, alkyl and substituted alkyl, alkoxy and substitutedalkoxy, and cycloalkyl and substituted cycloalkyl. The substituents onthe substituted members are selected from the group consisting of nitro,chloro, fluoro, acetoxy, acetamide, phenyl, benzyl, alkyl, alkoxy andcycloalkyl. Alkyl and alkoxy have from 1 to 9 carbon atoms andcycloalkyl has from 3-to 8 carbon atoms.

The members (a) to (e) are connected to [A] through divalent chemicallycompatible derivative members. The members (a) to (e) may be connectedto [A] through a divalent chemically compatible derivative member of thegroup consisting of Si(R) carbonate, carboxylate, sul fone, --O--,

alkyl and substituted alkyl, cycloalkyl and substituted cycloalkyl,urethane and substituted urethane, urea and substituted urea, amide andsubstituted amide, amine and substituted amine, and aryl and substitutedaryl. The alkyl members have from 1 to 9 carbon atoms, the aryl membersare either phenyl or naphthyl, and the cycloalkyl members have from 3 to8 carbon atoms with R and said members substituted being defined above.B is a member of the group consisting O-, --S, and NR-+.

The member [A] is polyvalent; free of reactive carbonto-carbonunsaturation; free of highly water-sensitive members; and consisting ofatoms selected from the group consisting of carbon, oxygen, nitrogen,chlorine, bromine, fluorine, phosphorus, silicon and hydrogen.

The polyene component has a molecular weight in the range from about 64to 20,000, preferably about 200 to about 10,000, and a viscosity in therange from essentially 0 to 20 million centipoises at 70 C. as measuredby a Brookfield Viscometer.

The polythiol component has a molecular weight in the range from about50 to about 20,000 and the general formula:

wherein R is a polyvalent organic moiety free from reactivecarbon-to-carbon unsaturation and n is at least 2. The ene/thiol moleratio is selected, so as to provide a solid, self-supporting curedproduct under ambient conditions in the presence of a free radicalgenerator.

More particularly, the member [A] of the polyene composition may beformed primarily of alkyl radicals, phenyl and urethane derivatives,oxygenated radicals, and nitrogen substituted radicals. The member [A]may also be represented by the formula:

wherein and k are integers greater than 1; R is a member of the groupconsisting of hydrogen, and alkyl having 1 to 9 carbon atoms; R is amember of the group consisting of hydrogen, and saturated alkyl having 1to 9 carbon atoms; R, is a divalent derivative of the group consistingof phenyl, benzyl, alkyl, cycloalkyl, substituted phenyl, substitutedbenzyl,-substituted alkyl and substituted cycloalkyl; with the termsalkyl, cycloalkyl and members substituted being defined above.

General representative formulas for the polyenes of the presentinvention may be prepared as exemplified in the following example. i

III.-Poly(alkylene-ether)plyol reacted with polyisocyanate andunsaturated monoaleohol forming polyurethane polyenes and relatedpolymers v I Ditunetional Eletratunctional' H v i hydrogen,'phenyl,cycloalkyl, and alkyl.

The novel class of polyenes of this invention derived I from carbon tocarbon unsaturated monoisocyanates may be characterized by extreme easeand versatility of manufacture when the liquid functionality desired isgreater than about three. For example, consider an attempted synthesisof a polyhexene starting with an'OH terminated polyalkylene ether hexolsuch as Niax Hexol LS-49O (Union general method of forming one type ofpolyene contammg urethane groups is to react a polyol ot the generalformula Rn OH) wherein "R is a polyvalent organic moiety free fromreactive carbon-to-carbon unsaturation and n is at least 2;

with a polyisocyanate of the general formula 0 wherein R is a polyvalentorganic moiety free from reactive carbon-to-carbon unsaturation and n isat least 2 andamember of thef'group-consisting of an ene-ol, yneol, eneamine and yne-a'm'ine. The reaction iscarri'ed out in an inertmoisture-free atmosphere (nitrogen blanket) Carbide Corp.) having amolecular weight of approxiat atmospheric Pressure at a tempfl'atlll'eill the range mately 700, and a viscosity of 18,720 cps. at 20 C. Anattempt to terminate this polymer with ene groupsby' reacting one moleof hexol with 6 moles of tolylene diisocyanate (mixed-2,4-, -2-6-isomerproduct) and 6 moles otallyl' alcohol proceeded nicely but resulted in aprematurely chain extended and crosslinked solid product rather than" anintended liquid polyhexene. Using the monoisocyan'ate route, however,this premature chain extension may be avoided and the desiredpolyurethane-containing liquid polyhexene may be very easily prepared bya simple; onestep reaction of one mole of hexol with 6 moles of allylisocyanate. This latter polyhexene has the added advantage of beingcured using the teachings of this invention to a 5 non-yellowingpolythioether polyurethane product. Simfrom 0 to about 120 C. for aperiod of about 5 minutes to-about 25 hours; -In the case where anene-olor yne-ol isemployed, the reaction is preferably a one step reactiortwherein all the reactants are charged together. In the case where anene-amine or yne-amine is used, the reaction is preferably a. two' stepreaction wherein the polyol and the polyisocyanateare reacted togetherand thereafter The group consisting of ene-ol, yne-ol, cue-amine andyneamine are usually added to the reaction in an amount such thatw thereis one carbon-to-carbon unsaturation in the polyoland, group member areadded in combination in a ilarly, the unsaturated monoisocyanatetechnique may be stoichiometric amount necessary to react with theisohol, partially hydrolized polyvinyl acetate,""and the like?" andhighly functional polyamines such as 'tetraethylene pentamine,polyethyleneimine, and the like.

'cya'nategroups in the polyisocyanate.

A second general method of forming a polyene containin'g'ur'ethanegroups (or urea groups) is to react a polyol (or polyamine) with anene-isocyanate or an yne-isocyanate to form the corresponding polyene.The general procedure and stoichiometry of this synthesis route issimilar to that described for polyisocyanates in the preceding. In thisinstance, a polyol reacts with an ene-isocyanate to form thecorresponding polyene. It is found, however, that products derived fromthis route, when cured in the presence of a chemical free radicalgenerating reagent and a polythiol, may form relatively weak solidpolythioether products. To obtain stronger cured products, it isdesirable to provide polar functional groupings within the main chainbackbone of the polymeric polyene. These polar functional groupingsserve as connecting linkages between multiple repeating units in themain chain series, and serve as internal strength-reinforcing agents byvirtue of their ability to create strong interchain attraction forcesbetween molecules of polymer in the final cured composition.

Polyenes containing ester groups may be formed by reacting an acid ofthe formula wherein R is a polyvalent organic moiety free from reactivecarbon-to-carbon unsaturation and n is at least 2; with either an ene-o1or yne-ol. The reaction is carried out in an inert moisture-freeatmosphere (nitrogen blanket) at atmospheric pressure at a temperaturein the range from to about 120? C. for a period of 5 minutes to 25hours. Usually the reaction is carried out in the presence of a catalyst(p-toluene sulfonic acid) and in the presence of a solvent, e.g. benzeneat refluxing temperature. The water formed is azeotroped off of thereaction.

Another method of making an ester containing polyene is to react apolyol of the formula wherein R is a polyvalent organic moiety free fromreactive carbon-to-carbon unsaturation and n is at least 2; with eitheran ene-acid or an yne-acid. The reaction is carried out in the samemanner as set out above for the ester-containing polyenes. In practicingthis latter technique, however, it may be found that ene-acids (oryneacids) in which the ene (or yne) group is adjacent to an activatingpolar moiety such as and the like are generally not desirable within thescope of this invention. These activated ene compounds are very prone toself-polymerization reactions to form vinyl polymers. Excessive amountsof self-polymerization of the ene groups is an undesirable side reactionint he present invention since the desired polythioether reactionproducts are precluded whenever self-polymerization of the ene groupsoccurs. Finally, the presence of activated, easily self-polymerizableene groups in the composition leads to oxygen inhibition during curing,storage stability problems, or the need for excessively high inhibitorconcentrations.

In forming the urethane-containing polyenes of the present invention,catalytic amounts of a catalyst may be empolyed to speed up thereaction. This is especially truein the case where an ene-o1 is used toform the polyene. Such catalysts are well known to those in the art andinclude organornetallic compounds such as stannous octoate, stannousOleate, dibutyl tin dilaurate, cobalt acetylacetonate, ferricacetylacetonate, lead naphthanate and dibutyl tin diacetate.

In summary, by admixing polyenes or polyynes containing two or morereactive unsaturated carbon-to-carbon bonds located terminal from themain chain with a polythiol containing two or more thiol groups permolecule and thereafter exposing said liquid mixture to a chemical freeradical generating reagent, there is provided an eswhere n is at least 2and R is a polyvalent organic moisentially odorless solid elastomeric orresinous polymeric product.

Polythiol as used herein refers to simple or complex organic compoundshaving a multiplicity of pendant or terminally positioned SH functionalgroups per average molecule.

On the average the polythiol must contain 2 or more SH groups/moleculeand have a viscosity range of essentially 0 to 20 million centipoises(cps) at 70 C. as measured by a Brookfield Viscometer either alone orwhen in the presence of an inert solvent, aqueous dispersion orplasticizer. Operable polythiois in the instant invention usually havemolecular weights in the range about 50 to about 20,000, and preferablyfrom about to about 10,000.

The polythiols operable in the instant invention may be exemplified bythe general formla ety free from reactive carbon-to-carbon unsaturation.Thus R may contain cyclic groupings and hetero atoms such as N, P or Oand primarily contains carbon-carbon, carbon-hydrogen, carbon-oxygen, orsilicon-oxygen containing chain linkages free of any reactivecarbon-tocarbon unsaturation.

One class of polythiols operable with polyenes to obtain essentiallyodorless polythioether products are esters of thiol-containing acids ofthe formula Where R is an organic moiety containing no reactivecarbon-to-carbon unsaturation with polyhydroxy compounds of structurewhere R is an organic moiety containing no reactive carbon-to-carbonunsaturation, and n is 2 or greater. These components will react undersuitable conditions to give a polythiol having the general structure:

0 R D-0 -R -SH) where R and R are organic moieties containing noreactive carbon-to-carbon unsaturation, and n is 2 or greater.

Certain polythiols such as the aliphatic monomeric polythiols (ethanedithiol, hexamethylene dithiol, decamethylene dithiol,tolylene-2,4-dithiol, and the like, and some polymeric polythiols suchas a thiol-terminated ethylcyclohexyl dimercaptan polymer, and the like,and similar polythiols which are conveniently and ordinarily synthesizedon a commercial basis, although having obnoxious odors, are operable butmany of the end products are not widely accepted from a practical,commercial point of view. Examples of the polythiol compounds preferredbecause of relatively low odor level include but are not limited toesters of thioglycolic acid a-mercaptopropionic acid (HS-CH(CH )COOH andB-mercaptopropionic acid (I'IS-CHzOHgCOCH) with polyhydroxy compoundssuch as glycols, triols, tetraols, pentaols, hexaols, and the like.Specific examples of the preferred polythiols include but are notlimited to ethylene glycol bis(thioglycolate), ethylene glycolbis(;8-mercaptopropionate), trimethylolpropane tris (thioglycolate),trimethylolpropane tris(fl-mercaptopropionate), pentaerythritol tetrakis(thioglycolate) and pentaerythritol tetrakis (fl-mercaptopropionate),all of which are commercially available. A specific example of apreferred polymeric polythiol is polypropylene ether glycolbisQS-mercaptopropionate) which is prepared from polypropylene-ether 1 lglycol (e.g. Pluracol P2010, Wyandotte Chemical Corp.) andB-mercaptopropionic acid by esterification. I

The preferred polythiol compounds are characterized by a low level ofmercaptan-like odor initially, and after reaction, give essentiallyodorless polythioether end products which are commercially attractiveand practically useful resins or elastomers for both indoor and outdoorapplications. I

Prior to curing, the curable liquid polymer may be formulated for use as100% solids, or disposed in organic solvents, or as dispersions oremulsions in aqueous media.

The curable liquid polymer compositions prior to curing may readily bepumped, poured, siphoned, brushed, sprayed, doctored, or otherwisehandled as desired. Following application, curing in place to a solidresin or elastomer may be effected either very rapidly or extremelyslowly as desired by manipulation of the compound ing ingredients andthe method of curing.

The liquid polythioether-forming components and compositions, prior tocuring, may be admixed with or blended with other monomeric andpolymeric materials such as thermoplastic resins, elastomers orthermosetting resin monomeric or polymeric compositions. 'The resultingblend may be subjected to conditions for curing or cocuring of thevarious components of the blend to give cured products having unusualphysical properties.

Although the mechanism of the curing reaction is not completelyunderstood, it appears most' likely that the curing reaction may beinitiated by most any chemical free radical generating reagent whichdissociates or abstracts a hydrogen atom from an SH group, or accomplishes the equivalent thereof. Generally the rate of the curing reactionmay be increased by increasing the temperature of the composition at thetime of initiation of cure. In many applications, however, the curing isaccomplished conveniently and economically by operating at ordinary roomtemperature conditions. Thus for use in elastomeric sealants, it ispossible merely to expose the polyene and polythiol admixture to achemical free radical generating reagent such as oxygen containing gasand obtain a cured solid elastomeric or resinous product.

By proper choice of type and concentration of chemical free radicalgenerating reagent, the curing period required for conversion of thepolyene/polythiol composition from the liquid to the solid state may bevaried greatly as desired. In combination with suitable accelerators orretarders, the curing period in the presence of the various chemicalfree radical generating'reagents may vary from about a few minutes orless to about 30 days or more. In general, the short curing periodsareachieved in applications where thin films of curable composition arerequired, such as in the field of coatings, whereas the long curingperiods are achieved and desired where more massive layers ofcomposition are required, such as in the field of elastomeric sealants.

' Chemical free radical generating reagents operable in this inventioninclude oxygen; ozone, chlorine; organic peroxides and hydroperoxides;peracids; persulfates; in organic peroxides; and and compounds such asazobisisovaleronitrile. Certain of these compounds may be made moreeffective and efiicient if used in conjunction with co-agent curing rateaccelerators. Examples of accelerated systems may include benzoylperoxide with dimethylaniline as an accelerator; cumene hydroperoxidewith cobalt naphthenate as an accelerator; and the like. Included inthis class are reagents or components which are generated in situ inthe'composition. Curing periods may be varied, but the reactions aregenerally relatively fast. Conversions from liquid to solid state mayoccur within a few minutes.

The chemical free radical generating reagent is usually added in anamount ranging from about 0.0005 to about 25% by weight of thephotocurable composition, with the preferred range being from about 0.05to about 5% by weight.

Conventional curing inhibitors or retarders which may be used in orderto stabilize the components or curable compositions so as to preventpremature onset of curing may include hydroquinone; p-tert.-butylcatechol; 2,6-ditert.-butyl-pmethylphenol; phenothiazine; N-phenyl-Q-naphthylamine; inert gas atmospheres such as helium, argon, nitrogen andcarbon dioxide; vacuum; and the like.

To obtain the maximum strength, solvent resistance, creep resistance,heat resistance and freedom from tackiness, the reaction componentsconsisting of the polyenes and polythiolsof this invention areformulated in such a manner as to give solid, crosslinked, threedimensional network polythioether polymer systems on curing. In order toachieve such infinite network formation the individual polyenes andpolythiols must have a functionality of at least 2 and the sum of thefunctionalities of the polyene and polythiol components must always begreater than 4. Blends and mixtures of the polyenes and'the polythiolscontaining said functionality are also operable herein.

The compositions to be cured, i.e. (converted to solid resins orelastomers) in' accord with the present invention may, if desired,include such additives as antioxidants, accelerators, dyes, inhibitors,activators, fillers, pigments, antistatic agents, flame-retardantagents, thickeners, thixotropic agents, surface-active agents, viscositymodifiers, extending oils, plasticizers, tackifiers and the like withinthe scope of this invention. Such additives are usually preblendedwith'the polyene orpolythiol prior to or during the compounding step.Operable fillers include natural and synthetic resins, carbon black,glass fibers, wood flour, clay, silica, alumina, carbonates, oxides,hydroxides, silicates, glass flakes, glass beads, borates, phosphates,diatomaceous earth, talc, kaolin, barium sulfate, calcium sulfate,calcium carbonate, antimony oxide and the like. The aforesaid additivesmay be present in quantities up to 500 parts or more per parts polymerby weight and preferably about 0.0005 to about 300 parts on the samebasis.

The compounding of the components prior to curing may be carried out inseveral ways. For example, the polyene, the polythiol and any otherinert additives may be admixed in an inert atmosphere and charged to anoxygenfree aerosol can, drum, tube, or cartridge for subsequent use.Exposure of admixed components to the atmosphere under ambientconditions will initiate curing. To initiate instantaneousoxygen-initiated curing, it is possible to merely admix the polyene andthe polythiol under atmospheric conditions in the absence of stabilizersor inhibitors. I

The mole ratio of ene/thiol for preparing the curable composition isfrom about 0.2/1 to about 5/1, and desirably about 0.75/1 to about1.5/1.

The following examples will aidin explaining, but should not be deemedas limiting, the instant invention. In all cases, unless otherwisenoted, all parts and percentages are by weight.

FORMATION OF POLYENE PREPOLYMER Example 1 458 g. (0.23 mole) of acommercially available liquid polymeric diisocyanate sold under thetrade name Adiprene L-100 by E. I. du Pont de Nemours. & Co. was chargedto a dry resin kettle maintained under a nitrogen atmosphere andequipped with a condenser', stirrer, thermometer, and gas inlet andoutlet. 37.8 g. (0.65 mole) of allyl alcohol was charged to the kettleand the reaction was continued for 17 hours with stirringv at 100 C.Thereafter the nitrogen atmosphere was removed and the kettle wasevacuated 8 hours at 100 C 50 cc. dry benzene was added to thekettle andthe reaction product was azeotroped with benzene to remove the unreactedalcohol. This allylterminated liquid prepolymer had a molecular weightof approximately 2100 and will be referred to as Prepolymer Ahereinafter.

Example 2 400 g. (0.2 mole) of Adiprene L-100 was charged to a dry resinkettle maintained under nitrogen and equipped with a condenser, stirrer,thermometer and gas inlet and outlet. 25.2 g. (0.43 mole) of propargylalcohol (HCECCH2OH) was added to the kettle and the reaction wascontinued with stirring for 18 hours at 160 C. Thereafter the nitrogenatmosphere was removed and the kettle was evacuated 16 hours at 100 C.followed by azeotropic distillations with 50 cc. water and then 50 cc.benzene to remove any excess propargyl alcohol. This HCEC- terminatedliquid prepolymer had a viscosity of 27,500 centipoises at 70 C. and amolecular weight of 2100 and will be referred to as Prepolymer Bhereinafter.

Example 3 1 mole of commercially available poly(ethylene ether) glycolhaving a molecular weight of 1450 and a specific gravity of 1.21 wascharged to a resin kettle maintained under nitrogen and equipped with acondenser, stirrer, thermometer and a gas inlet and outlet. 2.9 g.dibutyl tin dilaurate as a catalyst was charged to the kettle along with2 moles tolylene-2,4-diisocyanate and 2 moles of allyl alcohol. Thereaction was continued with stirring at 60 C. for 2 hours. Thereafter avacuum of 1 mm. was applied for 2 hours at 60 C. to remove the excessalcohol. This CH CH terminated prepolymer had a molecular weight ofapproximately 1950 and will hereinafter be referred to as Prepolymer C.

Example 4 1 mole of a commercially available poly(propylene ether)glyco1having a molecular weight of about 1958 and a hydroxyl number of 57.6was charged to a resin kettle equipped with a condenser, stirrer,thermometer and a gas inlet and outlet. 4 g. of dibutyl tin dilaurate asa catalyst was added to the kettle along with 348 g. (2.0 moles) oftolylene-2,4-diisocyanate and 116 g. (2 moles) of allyl alcohol. Thereaction was carried out for 20 minutes at room temperature undernitrogen. Excess alcohol was stripped from the reaction kettle by vacuumover a 1 hour period. The thus formed CH =CH- terminated liquidprepolymer had a molecular weight of approximately 2400 and willhereinafter be referred to as Prepolymer D.

Example 5 750 g. of a N-containing tetrol (hydroxyl functionality=4)available from Wyandotte Chemicals Corp. under the trade name TetronicPolyol 904 having a M.W. of 7,500 was placed in a reaction vessel heatedat 110 C. The flask was maintained under vacuum for 1 hour. Then, underan atmosphere of nitrogen, 0.1 cc. dibutyl tin dilaurate was added andthe flask was cooled to 50 C. Now 18.3 g. allyl isocyanate was addedslowly, maintaining the temperature at about 95 C. for about 1 hourafter the addition was completed. The thus formed polymeric polyene(i.e., Prepolymer E hereinafter) had a theoretical allyl functionalityof 2.2, a theoretical hydroxyl functionality of 1.8, and a calculatedmolecular weight of about 7,683.

Example 6 To a resin kettle maintained under a nitrogen atmosphere andequipped with a condenser, stirrer, thermometer and gas inlet and outletwas added 843 g. of a commercially available liquid diisocyanateprepolymer sold under the trade name Multrathane F-196 by Mobay ChemicalC0,. said prepolymer having a molecular weight of about 1680 and anavailable isocyanate content of 4.7-5.2%. 87 g. (1.5 moles) of allylalcohol was added to the kettle and the reaction was continued for 18hours at 140 C. with stirring. Thereafter the nitrogen atmosphere wasremoved and the kettle was evacuated for 22 hours at 100 C. 50 cc. ofdry benzene was added to the kettle and the reaction product wasazeotroped therewith to remove any un- 14 reacted alcohol. This CH =CH-terminated liquid prepolymer had a viscosity of 25,000 centipoises at 70C. and a molecular weight of approximately 1800 and will be referred toas Prepolymer F hereinafter.

Example 7 678 g. (0.34 mole) of a commercially available poly-(propylene ether) glycol sold under the trade name NIAX by Union CarbideCo. and having a molecular weight of about 2025 was degassed for 2 hoursat C. and thereafter charged to a resin kettle maintained under anitrogen atmosphere and equipped with a condenser, stirrer, thermometerand gas inlet and outlet. 118 g. (0.68 moles) of tolylene2,4-diisocyanate was charged to the kettle and the reaction was heatedwith stirring for 2% hours at 120 C. After cooling, 58 g. (1.0 mole) ofallyl alcohol was added to the kettle and the mixture was refluxed at120 C. for 16 hours under nitrogen. Excess allyl alcohol was removedovernight by vacuum at 100 C. Half of the allyl terminated liquidprepolymer having a viscosity of 19,400 cps. at 30 C. as measured on aBrookfield Viscometer was removed from the kettle and will be referredto hereinafter as Prepolymer G. The other half portion of the prepolymerwas combined with 50 cc. of dry benzene and azeotroped overnightfollowing which excess benzene was pulled out under vacuum for 5 hoursat 120 C. This portion of the allyl-terminated liquid prepolymer had aviscosity of 15,600 cps. at 70 C. as measured on a Brookfield Viscometerand a molecular weight of ap proximately 2500 and will hereinafter bereferred to as Prepolymer H.

Example 8 and equipped with a condenser, stirrer, thermometer and gasinlet and outlet. 132 g. (0.76 moles) of tolylene-2,4-diisocyanate wasas charged to the kettle and the kettle was heated for 2 hours at 120 C.with stirring under nitrogen. After cooling 58 g. (1.0 mole) of allylalcohol was added and the mixture was refluxed at 120 C. overnight.Excess allyl alcohol was stripped by vacuum overnight at 120 C. The thusformed allyl terminated liquid prepolymer had a viscosity of 15,000 cps.as measured on a Brookfield Viscometer at 70 C. and a molecular weightof approximately 2500 and will hereinafter be referred to as Prepolymer1.

Example 9 To a 1 liter resin kettle equipped with stirrer, thermometer,gas inlet and outlet and heated to a temperature of 50 C. was charged610 g. (0.2 mole) of poly(tetramethylene ether) glycol, commerciallyavailable from Quaker Oats Co. and having a hydroxyl number of 37.1along with 0.3 g. dibutyl tin dilaurate. The temperature of the kettlewas raised to C. and the contents were freed of water under 1 millimetervacuum for 1 hour. The resin kettle was cooled to 60 C. and the systemwas placed under a protective atmosphere of nitrogen throughout theremainder of the reaction. 25.2 g. of allyl isocyanate, (0.4 mole) wasadded dropwise to the kettle at such a rate as to maintain thetemperature at 60 C. When the NCO content dropped to 0.54 mg./g., 1 mm.vacuum again was applied and the system was heated at 70 C. for onehour. The thus formed polymer product was a solid at room temperaturebut at 50 C. is clear and pourable. The polymer product had a viscosityof 1,800 centipoises at 70 C. as measured on a Brookfield Viscometer andan average molecular weight of approximately 3200.

Example 10 To a 1 liter resin kettle equipped with stirrer, thermometer,gas inlet and outlet was charged 591 g. (0.30 mole) of a poly(propyleneether) gylcol commercially available from Union Carbide under the tradename PPG-2025 and 0.3 g. of dibutyl tin dilaurate. The kettle was heatedto 110 C. and the contents were freed of water under 1 mm. vacuum for 1hour. The kettle was cooled to 25 C. and the system was placed under aprotective atmosphere of nitrogen throughout the remainder of thereaction. 53.1 ml. (49.8 g., 0.6 mole) of allyl isocyanate commericallyavailable from Chemetron Corp. was added to the system. An exothermcarried the temperature to 45 C. in 22 minutes. After 60 minutes, theNCO content (as determined by titration) was 0.04 mg./g. The system wasplaced under 1 mm. vacuum and heated to 70 C. to remove traces ofunreacted allyl isocyanate. The resultant polymer product had aviscosity of 600 centipoises at 30 C. as measured on a BrookfieldViscometer and an average molecular weight of approximately 2200.

The next two examples show a method of preparing the polyenes of theinstant invention by dehydration of polyether glycols.

Example 11 100 g. of po1y(propylene ether) glycol commercially availablefrom Union Carbide under the trade name PPG-2025 was poured through ahot tube filled with aluminum oxide at such a rate that the entirereaction took place in 2 hours. The tube was 1" in diameter with thereaction zone 1 ft. long and completelyenclosed within a tube furnace.The alumina catalyst was -18 mesh and was maintained at 350 C. using aLindberg Hevi-Duty tube furnace. The tube was fitted with a droppingfunnel and a nitrogen inlet at the top. Nitrogen pressure was kept onthe system throughout the reaction. The product collected from thebottom of, the tube was analyzed for unsaturation by the mercuricacetate titration method and was found to have 100% of the theo reticalamount of unsaturation expected after dehydration of both terminalhydroxyl groups of the poly(propylene ethyl) glycol. The polyene producthad a viscosity of 125 cps. at 70 C. and an average molecular weight ofapproximately 2000.

Example 12 1 kilogram of poly(propylene ether) glycol commerciallyavailable from Union Carbide under the trade name -PPG-2025 was heatedto 120 C. in a round bottom flask. To this was added 120 ml. excess) ofacetic anhydride at such a rate that the temperature of the mixture waskept at 120-140 F. Following the addition, the mixture was heated at 140C. for 4 hours. It was then cooled and diluted with an equal volume ofchloroform, washed with 10% aqueous sodium carbonate, then with water.The organic layer was separated and the chloroform was removed bydistillation. Infrared analysis of the purified material showed it to bethe diacetate of the poly- (propylene ether) glycol with no residualhydroxyl groups.

100 g. of this diacetate was put through the hot tube as in Example 11except that the packing was glass helices instead of alumina and thetemperature was 375 C. The product contained 64% of the theoreticalamount of unsaturation expected after the elimination of acetic acidfrom both terminal acetoxy groups of the poly(propylene ether) glycoldiacetate.

Example 13 100 g. of hexol sold under the trade name NIAX Polyol LS-490by Union Carbide Chemicals Co. having a molecular weight of 684 wascharged to a 1 liter 4 neck flask and heated to 110 C. under vacuum andnitrogen for 1 hour. It was then cooled to approximately 60 C. whereat0.1 cc. of dibutyl tin dilaurate was added followed by slowly adding 83g. (1 mole) of allyl isocyanate to keep the temperature in the range7080 C.

16 during the addition. After addition, the reaction was allowed tocontinue for 1 hour at 70 C. The polymeric hexaene product obtained hadan average molecular weight of approximatey 1200 and a viscosity of 300centipoises at 70 C.

- Example 14 Example 15 To a 1 liter 4 neck flask was charged 100 cc. ofdimethylformamide, 100 g. of tolylene-2,4-diisocyanate and 0.1 cc.dibutyl tin dilaurate. 58 g. of hexol, i.e. NIAX Polyol LS*.4.90 byUnion Carbide and 34 g. of allyl alcohol were mixed together and addeddropwise to the flask. Before the addition to the flask was completed,the reaction, which was exorthermic, gelled and the addition wasdiscontinued. i

A comparison of Examples 13, 14 and 15 shows that Example 13 is animprovement over Examples 14 and 15 in that it allows one to formpolymer without the necessity of a solvent. A comparison of Examples 14and 15 shows that when starting with a highly functional polyol usingthe diisocyanate/allyl alcohol technique one must operate in dilutesolution to avoid premature crosslinking (i.e., gelation) which rendersthe polyene product useless as a curable liquid prepolymer. This problemis avoided completely by using the unsaturated monoisocyanate techniqueillustrated in Example 13.

Example 16 [In a 1 liter, 4 neck flask 220 g. of hexol commerciallyavailable from Union Carbide Chemicals Co. under the trade name NIAXPolyol LS-490 (0.32 mole) and 0.1 cc. of dibutyl tin dilaurate washeated to 110 C. under vacuum for 1 hour. After cooling in nitrogen toapproximately 60 C., g. of allyl isocyanate was added to the flask bymeans of a dropping funnel. The exothermic reaction produced atemperature of C. When the addition was complete the reaction wascontinued at 70 C. for 1 hour. The resulting triene polymer product hadan average molecular weight of approximately 950 and a viscosity of 300centipoises as measured on a Brookfield Viscometer at 70 C.

Example 17 To a 1 liter 4 neck flask was charged 300 g. of a polyesterdiol (molecular weight 3232) sold under the trade name RC Polyester S101-35 by R. C. Division, Hooker Chemical Corp. and 0.1 cc. of dibutyltin dilaurate. The flask was heated to C. of dibutyl tin dilaurate. Theflask was heated to 110 C. under vacuum and maintained thereat for 1hour. The flask was cooled to approximately 60 C., nitrogen wasadmitted, and 7.7 g. allyl isocyanate and 8.1 g. oftolylene-2,4-diisocyanate was added by means of a dropping fnnnel to thereaction at a moderate rate. A maximum temperatureof 90 C. was needed.When the addition was complete the reaction was allowed to continue at70 C. for 1 hour. The thus formed solid polymeric producthad an averagemolecular weight of approximately 6800 and a viscosity of13,600centipoises when measured on a Brookfield Viscometer at 70 C.

1 7 Example 18 To a 1 liter 4 neck flask heated at 110 C. was charged808 g. of a polyester diol (having a molecular weight 3232) sold underthe trade name R'C Polyester S 101- 35 by R. C. Division, HookerChemical Corp. and 0.1 cc. dibutyl tin dilaurate. The flask wasmaintained under vacuum at 110 C. for 1 hour. The flask was cooled toapproximately 50 C. and with nitrogen passing through, a mixture of 10g. of allyl alcohol and 60 g. of tolylene- 2,4-diisocyanate was addedvia a dropping funnel at a 25 moderate rate. The reaction was allowed tocontinue for 15 minutes. A maximum temperature of 90 C. was produced bythe exothermic reaction. The polymeric product obtained was a solid atroom temperature but liquid at 70 C. The product had an averagemolecular weight 30 of approximately 10,500 and a viscosity of 270,000centipoises at 70 C.

Example 19 Following the procedure of Example 12 and using necessaryreactants, a polyene of the following formula was prepared:

Example 20 Following the procedure of Example 3, and using necessaryreactants, a polyene of the following formula was prepared:

L CH3 Example 22 Following the procedure of Example 3, and usingnecessary reactants, a polyene of the following formula was prepared:

Example 23 Following the procedure of Example 3, and using necessaryreactants, a polyene of the following formula was prepared:

Examples 24-42 Following the general procedure of the prior examples,and using the necessary reactants, a series of polyenes having theformula:

T'ABLEC0ntinued 40-- f None ON (CH2) CH=CH HO -CH2CH2OH Poly (ethyleneether) glycol, 1 mole 4-pentenylyisoeyante, 2 moles 41 Pluraco1 208 DDIDiisocyanate CHzO CHzCH=CHz HO-CH2 C H H 0 CHzCH=CH2 Phosphorus-basedployol-Wyandotte Chem. Dimer acid-based diisocyanate-Generall,l,1-trlmethylolpropanediallyl ether,

00., 1 mole Mills 00., 2 moles 2 moles 42--.- CH CH3 O OCN-CHCH2CH2NOO110- 11-0112 onion-on (EH A HOCHz-CHN$|J m a N-CH2CHz-N H H CHCHHO-CH-GH2 CHzCH-OH CH2 H3 CH3 N,N,N,N-tetrakis(2-hydroxyprppyl)-ethy1ene diamine-Wyandotte 00., Quadrol, 1 mole2,7-di(isoeyanato)-heptane, 4 moles N-2 (-furyl) -N-vlnyl ethanolaimine,

4 moles CHEMICAL CURING PROCESS Example 43 0.005 mole of theallyl-terminated liquid Prepolymer A was charged to a 2 02. glass jaralong with a straight stoichiometric amount of a polythiol to reactantwith the CH =CH groups of the polyene, i.e., 0.0025 mole ofpentaerythritol tetrakis(thioglycolate) having a molecular weight of432. The liquid reactants were mixed together and stirred frequentlywhile heating for /2 hour at 130C. Thereafter the reactants were leftindoors under ambient conditions at atmospheric pressure. At the end ofa one week period, a solid, odorless, elastomeric, cured polythioetherpolymer resulted.

Example 45 Example 44 was repeated except that 0.0025 mole ofpentaerythritol tetrakis (,G-mercaptopropionate), molecular weight 488,was substituted for the pentaerythritol tetrakis(thioglycolate) inExample 44. After a one week period, a solid, odorless, elastomeric,cured polythioether polymer resulted.

Example 46 Example 44 was repeated except that 0.0033 mole oftrimethylolpropane tris(,B-mercaptopropionate) having a molecular Weightof 398 was substituted for the pentaerythritol tetrakis(thioglycolate).The reaction mixture began curing when taken from the oven and a solid,odorless, self-supporting, cured elastomeric polythioether polymerresulted after 1 /2 days.

Example 47 0.005 mole of the allyl-terminated liquid Prepolymer E wascharged to a 2 oz. glass jar along with a stoichiO- metric amount of apolythiol to react with the allyl groups in Prepolymer E, 0.0036 mole oftrimethylolpropane tris (fl-mercaptopropionate). The liquid reactantswere stirred together briefly at room temperature and allowed to standunder ambient conditions. After eight hours a solid, odorless,self-supporting, cured elastomeric polythioether polymer resulted.

Example 48 Example 47 was repeated except that 0.0027 mole ofpentaerythritol tetrakis(fi-mercaptopropionate) was substituted for thetrimethylolpropane tris(flmercaptopropionate) and the reactants werestirred for /2 hourat C. before curing under ambient conditions. After 4hours a cured solid, odorless, self-supporting, elastomericpolythioether polymer resulted.

Example 49 0.005 mole of the HCEC terminated liquid Prepolymer B wascharged to a 2 oz. glass jar along with a stoichiometric amount to reactwith the HCEC- groups in Prepolymer B of trimethylolpropanetris(,8-mercaptopropionate) (0.0033 mole). The reactants were stirred together and stirred for 4 hours at 130 C. After a 2 week period a cured,solid, odorless, self-supporting, elastomeric polythioether polymerresulted.

Example 50 0.005 mole of the allyl-terminated liquid Prepolymer F wascharged to a 2 oz. glass jar along with a stoichiometric amount to reactwith the allyl groups of the Prepolymer, i.e., 0.0033 mole oftrimethylolpropane tris(B-mercaptopropionate) having a molecular weightof 398. The liquid reactants were stirred together for /2 hour at C.Thereafter the reactants were cured under ambient conditions. After 2 /2days the liquid reactants began curing and at the end of a 2 weekperiod, a solid, odorless, selfsupporting, cured elastomericpolythioether polymer resulted.

The following examples show the curing reaction of the instant inventionas catalyzed by a peroxide. In all the examples 10 g. of theallyl-terminated liquid polyene prepolymer were admixed in a 2 02. glassjar with a stoichiometric amount of a polythiol, i.e. pentaerythrioltetrakis (,G-mercaptopropionate) sufficient to react with all the allylgroups on the prepolymer. In addition, the peroxide was added along withan accelerator for the peroxide. The

a 25 a reactants were briefly stirred and then left to cure indoorsbient conditions. A self-supporting, solid, odorless, cured at ambientconditions. The results foliow: polythioether polymer resulted in lessthan 15 minutes.

Polyene Ex. No. prepolymer Peroxide (g.) Accelerator (g.) Curingobservations 51 I .1 g. benzoyl peroxide. 0.2 g. dimethyl aniline Curedinstantly while mixing. 52 I 0.4 g. of 69% cumenehydroperoxida. 0.1 g.cobalt napththanate Cured to a solid in 7 days. 53 I 0.1 g.cyclohexanone peroxide 0.2 g. dimethyl aniline and 0.01 g. cobaltnaphthanate Do.

The following Examples 54-59 show curing of filled Example 62compositions when catalyzed by oxygen. In all examples, g. of theallyl-terminated liquid prepolymer were charged to a 2 oz. glass jaralong with a stoichiometric amount of a polythiol curing agent, i.e.pentaerythritol tetrakis(fl-mercaptopropionate) and a filler. Themixture Example 61 was repeated except that 0.02 mole of diallylphthalate was substituted for the diallyl adipate. A self-supporting,solid, odorless, cured polythioether polymer product resulted in lessthan minutes.

was stirred briefly and then cured under ambient con- Exa m 63 ditions.A comparison of Examples 57 and 58 shows the necessity of having apolythiol present to obtain a cured Example 61 was repeated except thatole of d1- solid polymer. allyl succmate was substltuted for the diallyladipate.

Ex. Poly- N o. Preploymcr Filler thiol Curing observations 54... I 8.0g. Emtal Talc A Cured to an ordorless solid in 4 hrs. 55 I 8.0 g. Unimal303 A Do. 56... I 8.0 Desertalc A Cured to an odorless solid in 24 hrs.

1 4 57 I 3.0 g. HiSil 233 A Cured to an odorless solid in 1% hrs. 58---I 3.0 g. HiSil 233 None No cure after 30 days. 59. I 3.0 gbHiSil-l-Sg. ACured to an odorless solid in 4 hrs.

1 A=pentaerythritol tetrakis (fl-mercaptopropionate).

9 A tale commercially available from Eastern Magnesia Talc 00.,Burlington, Vt.

a Polyaluminum silicate manufactured by United Clay Mines, Trenton, N .J

4 An acicular platey talc commercially available from Desert Minerals11:10., Los Angeles,

reinforcing silica commercially available from Columbia SouthernChemical Corp., Pittsburgh, Pa.

The following examples show the operability of various Aself-supporting, solid, odorless, cured polythioether liquid polyene andpolythiol systems to form cured solid product resulted in 30 minutes.polymers by the process of the instant invention. Example 64 Example 6040 Example 61 was repeated except that 0.02 mole of 2,2-

1510 g. of a commercially available poly(oxypropy1- dial-lyloxypropanewas substituted for the diallyl adipate. ene) glycol sold under thetrade mark Pluracol P 2010 A self-supporting, solid, odorless, curedpolythioether by Wyandotte Chemical Corp. was chargred to a resinpolymer product resulted in less than 15 minutes. kettle maintainedunder a nitrogen atmosphere and Example 65 equipped with a condenser,stirrer, thermometer and gas inlet and outlet. The reactant was degassedat room temgrams mole) of y h h P Charged srature f 3 hours 5 f an 0%isomer to a 2 oz. glass bottle along mm a stoichiometric amount ture oftolyene2,4-diisocyanate and tolylene-2,6-diisocyaof P l react With thenyl groups in the diallyl Hate rgspfictively sold undelthe trade nameMondur TD amine, 1.e., 4.9 g. (0.01 mole) of pentaerythritol tetraxis 80was charged to the kettle and the kettle was heated for benzoyl Reroxideand 2 hours at with Stirring under nitrogen. There 0.1 g.dimethylanrlme. The reactants were stirred briefly. after 1163 (2 moles)of allyl alcohol was added to the In less than 15 minutes aself-supporting, solid, odorless, kettle and the mixture was refluxedfor 16 hours at 120 C. cured clear r ubbery Polythloether polymerresulted" Excess allyl alcohol was stripped by vacuum at 115 C. Thefollowing s hows l i example of the cufing for 23 hours The thus formedterminated of a polymer1c thlol-contammg compound and a vinylpolyeneprepolymer had a molecular weight of approxitermmated Polymer mately2460-2500, and a viscosity of 16,000 cps. as Example 66 measured on aBrookfield viscometer at 30 C. 1.5 moles of B-mercaptopropionic acid,0.5 mole of a .0005 mole of thusjfol'med P y and (1005 111016 ofcommercially available poly(propylene ether) glycol soldtrimethylolpropane triallyl ether were charged to a 2 oz. under thetrade name Pluracol P2010 by Wyandotte glass jar along with astoichiometric amount of the poly- Chemigal Corp, and 0.1 g,p-toluenesulfonic a id and 50 meric dithiol prepared in EXamplc 66- Aftr add ng 0.063 ml. benzene were charged to a resin kettle maintainedgram of benzoyl peroxide and 0.15 gram of dimethylunder a nitrogenatmosphere and equipped With a conaniline, the mixture in the glass jarwas immediately denser, stirrer, thermometer and gas inlet and outlet.The

stirred. Thereafter the mixture was poured into a plastic mixture washeated and the benzene-water azeotrope was mold for curing. Within 30minutes a solid, self-supportcollected. The actual amount of watercollected amounted ing, odorless, cured elastic polymer resulted. to17.5 g. The reaction was vacuum-stripped for several Example 61 hours at70 C. to remove benzene. The resulting polythiol polymer had a molecularweight of about 2210- grams mole) diallyl adipate Were charged to 2230and an average functionality of 2 and was cola 2 02. glass bottle alongwith a stoichiometric amount of 70 l d fo use h i a p y h to {react withthe F P in the 659 g. (0.145 mole) of a poly(propylene ether) triolallyl Q p mole) of Pentaerythritol commercially available from WyandotteChemical Corp. tetfakls (fl- P P P of lallfoyl P under the trade namePluracol TPE 4542 having a oxide and 0.15 g. dimethylaniline. Thereactants were molecular i ht f about 4500 d a h d number stirredbriefly and then placed on the bench top at amof 37.1, and 0.3 g. ofdibutyl tin dilaurate were charged to a resin kettle maintained under anitrogen atmosphere and equipped with a condenser, stirrer, thermometerand gas inlet and outlet. The reactants were maintained at 110 C. for 1hour and then cooled under nitrogen to room temperature. 25.2 g. (0.435mole) of allyl alcohol was added to the kettle followed by 75.7 g.(0.435 mole) of an 80-20% isomer mixture of tolylene-2,4-diisocyanateand tolylene 2,6-diisocyanate respectively sold under the trade nameMondur TD 80. The temperature reached 55 C. in 6 minutes. A sample wastitrated for NCO resulting in 6.02 mg. NCO/g. after 20 minutes. After 1hour the NCO titration showed 0.997 mg. NCO/g. The polyene polymer had amolecular weight of about 5200 and an average functionality of 3 and wasvacuum stripped at 70 C. for 1 hour and then collected. 0.003 mole ofthe polythiol polymeric material formed supra was charged to a 2 oz.glass jar along with 0.002 mole of the allyl-terminated polyene polymerformed herein, 0.10 g. benzoyl peroxide and 0.20 g. dimethylaniline. Thereactants were stirred briefly. In less than /2 hour a selfsupporting,solid, odorless, clear, cured polythioether polymer product resulted.

Example 67 3 grams of a linear saturated hydrocarbon backboneethylene/propylene/nonconjugated diene terpolymer commercially availableunder the trade name Nordel by E. I. de Pont de Nemours & Co., which hasbeen visbroken until it had a reduced specific viscosity of 0.99 andcontained 0.4 vinyl, 6.4 trans and 0.4 vinylidene unsaturated groups per1000 carbon atoms, were dissolved in 100 ml. of benzene in a glass jar.A 50% excess over the stoichiometric amount, i.e., 0.0006 rnole (0.3 g.)of pentaerythritol tetrakis (ti-mercaptopropionate) was added to the jarin addition to 0.015 g. benzoyl peroxide and 0.03 g. dimethylaniline.The glass jar was set aside under ambient conditions. After 24 hours thebenzene had substantially evaporated leaving a gelatinous polymericprecipitate. Acetone was added to precipitate more polymer. The polymerwas filtered off, washed with acetone and dried in a vacuum oven at 60C.

2.3 grams of the above polythioether polymer product was extracted withbenzene along with a control sample of the starting visbroken Nordelmaterial. The control sample showed a nil gel content (benzeneinsoluble) whereas the peroxide cured (crosslinked) solid polythioetherpolymer product had a gel content in excess of 50%.

Example 68 643 grams (0.32 mole) of a commercially availablepoly(propylene ether) glycol sold under the trade name Pluracol P 2010by Wyandotte Chemical Co. were degassed at room temperature for 1 hourand then charged to a resin kettle maintained under a nitrogenatmosphere and equipped with a condenser, stirrer, thermometer and gasinlet and outlet. 111.4 grams (0.64 mole) of an 80 20% isomer mixture oftolylene-2,4-diisocyanate and tolylene2,6-diisocyanate, respectively,sold under the trade name Mondur TD 80, were added to the kettle. After45 minutes, the temperature was raised to 120 C. and the reaction wascontinued for 50 minutes. A sample was removed and titrated for NCO,resulting in 33.54 mg. NCO/g. 62.7 grams of diallyl amine were added at105 C. and the reaction was continued for minutes. A sample was titratedresulting in an NCO content of 1.20 mg. NCO/g. A vacuum was applied tothe kettle for 1 hour at 90 C. followed by cooling under nitrogen Theresulting product had a molecular weight of about 2540-2580 and an enefunctionality of 4.

10 grams of the thus-formed polymer were charged to a 2 oz. glass jaralong with 2 g. of pentaerythritol tetrakis- (fi-mercaptopropionate) and0.06 g. azobisisovaleronitrile. The liquid reactants were brieflystirred together and set aside under ambient conditions. Within 30minutes a solid, odorless, elastomeric, cured polythioether product wasobtained.

28 Example 69 215 grams of poly(ethylene imine) commercially availablefrom Dow Chemical Co. under the trade name Montrek 18 along with 41.5 g.allyl isocyanate were charged to a resin kettle maintained under anitrogen atmosphere and equipped with a condenser, stirrer, thermometerand gas inlet and outlet. The reactants were maintained at 70 to C.during addition. The reaction was continued for 1 hour at 70 C.

10 grams of the thus-formed polymer were charged to a 2 oz. glass jaralong with 1.5 g. of pentaerythritol tetrakis(p -mercaptopropionate) and0.25 g. of azobisisobutyronitrile. The mixture was briefly stirred andplaced in a warm room at about F. Within 2 hours a solid,self-supporting, odorless, cured polymer product was formed.

Example 70 The polymeric polythiol (0.003 mole, i=2) from Example 66 wasadmixed with a stoichiometric amount (0.002 mole, f=3) of a monomericpolyene, glycerol trioleate (triolein, molecular weight 885), 0.05 g.benzoyl peroxide and 0.10 g. dimethylaniline. The jar containing thereactants after mixing was set aside under ambient conditions. Within /2hour the liquid mixture was converted to a self-supporting, solid,odorless, clear, rubbery, cured polythioether product.

The following example shows the operability of the instant inventionwhen the polyene contains acetylenic linkages.

Example 71 400 grams (0.20 mole) of a commercially available liquidpolymeric diisocyanate sold under the trade name Adiprene L-100 by E. I.du Pont de Nemours & Co. were charged to a dry resin kettle maintainedunder a nitrogen atmosphere and equipped with a condenser, stirrer,thermometer and gas inlet and outlet. 25.2 grams (0.45 mole) ofpropargyl alcohol were charged to the kettle and the reaction wascontinued for 17 hours with stirring at 100 C. Thereafter the nitrogenatmosphere was removed and the kettle was evacuated 15 hours at 100 C.

10 grams of the propargyl terminated liquid prepolymer, 3.0 grams ofpentaerythritol tetrakisQS-mercaptopropionate), 0.06 gram of benzoylperoxide and 0.15 gram of dimethylaniline were admixed in a 2 oz. glassjar, stirred briefly and set aside under ambient conditions. Within /2hour a solid, odorless, self-supporting, cured, elastomeric polymerproduct resulted.

The following example shows the necessity of having a free radicalgenerator present, e.g., oxygen, in order to cure by the instantinvention.

Example 72 40 grams of Prepolymer I and 10 grams of a filler soldcommercially under the trade name Hi Sil 233 by Columbia SouthernChemical Corp. were charged under nitrogen to a 200 ml. round bottom3-necked flask maintained under a nitrogen atmosphere and mixedthoroughly. The flask was heated by a water bath to 60 C. under fullvacuum for 2 hours. The flask was then allowed to cool under vacuum. 4grams of pentaerythritol tetrakis(fimercaptopropionate) were charged tothe flask under nitrogen and the reaction was stirred continuously.After 6 /2 days under nitrogen, no cure was noted. The reaction was thenexposed to oxygen from the atmosphere and a solid, cured, odorless,elastomeric product resulted within 45 minutes.

Example 73 g. of Prepolymer E from Example 5 herein was charged to aErlenmeyer flask equipped with a magnetic stirrer and connected bytubing to another Erlenmeyer flask containing 54 g. oftrimethylolpropane tris(/3-mercaptopropionate). The system was evacuated(0.05 mm.) while heating the polymer to 100 C. with stirring. After 29 2hours all bubbling ceased. An additional /2 hour evacuation wasperformed. Thereafter the trimethylolpropane tris (B-mercaptopropionate)was poured into the flask containing Prepolymer E under nitrogen. Afterstirring to insure good mixing, heat was removed and the reaction 30 Thepolyene/polythiol mole ratio is selected so as to provide a solid finalcured product, i.e., one that is nonflowing and structurallyself-supporting under ambient conditions. In typical cases, as shown bythe examples, this ratio can be about 0.2 to moles thiol groups per wascontinued under nitrogen for 4 days. No curing was 5 mole ene groups. Ingeneral the mole ratios significantly observed. A sample of theunreacted material was reabove or below I tend to give a high proportionof chain moved from the Erlenmeyer flask under nitrogen and extension orgrafting whereas mole ratios near 1 give placed in a 2 oz. jar. Thesample was exposed to ambient predominantly chain extension andcrosslinking. Occaconditions indoors and in about 40 minutes evidence ofsionally, however, ratios necessary to give a solid as aforecuring(viscosity change) was observed. Within 8 hours, said may lie outsidethe stated range, and experimentation an odorless, solid, elastomeric,cured polymer product was may be necessary to determine a suitable ratioto give obtained. a solid. This experimentation is easily carried out,and

The following example shows the ability to retard the offers nodifficulties to those skilled in the art. Examples curing process of theinstant invention by the use of 758() and 81-86 show how to vary theratio and how antioxidants. one can empirically determine the amount ofpolythiol Example 74 necessary to react with the polyene to obtain asolid, selfsupporting, cured polymeric product.

10 of p y h E from p e 5 Was added to Examples 75-80 show the ability touse mixtures of the each of three 2 J To one of the J was aflded 3 2Opolythiols and how to empirically determine the amount ml. of benzenecontainlng 0.5% based on the weight of of l hi l necessary to f cured,Solid, lf tthe prepolymer of an antioxidant sold under the trade ingpolymeric products by the instant invention name Santonox commerciallyavailable from Monsanto As shown in Examples 5 30 grams f prepolymerChemical To another of the j cohtainihg p Y' I from Example 8 wereadmixed with varying ratios of a mer E was added 3 ml. of benzenecontaining 0 5% based mixture f polythiols and cured in the Presence f aPer- 0n the Welght 0f the p p y of an alltloxldaht l oxide withdimethylaniline as a peroxide activator. under the trade name Dalpac FGcommercially avail- In Examples 31 g 3. grams f prepolymer I f able fromHercules Powder Co. To the third ar was Example 3 were admixgd withvarying amounts f a polyadded 3 of benzene as To blend the thiol, i.e.,pentaerythritol tetrakis(,B-mercaptopropionate) ponents the jars wereheated in a forced draft oven set at along with 5 f 19% benzoyl peroxide(in benzene) for 25 minutes With frequent The J and 0.3 g. ofdimethylaniline. The mixture was briefly Were WlthdraWIl from the Ovenand gof tl'lmethylol' stirred in a 2 oz. glass jar and then transferredto a shal- P p tfts(fi'mereaptoptopiohate) Was added to each lowaluminum foil dish. The mixtures were then allowed 0f the j and curingWas initiated indoors under ambient to cure indoors under ambientconditions. The results of conditions. The control run, without anyantioxidant pres- 5 the amount of reactants necessary for aself-supporting ent, cured within /2 hour to a solid elastomeric polymerpolymeric structure are shown.

EXAMPLES 75-80 10% solution Polythiol mixture in benzene of benzoylDimethyl Curing Self- Example Polyene Q,43 151-23 peroxid aniline timeShore A supporting number polymer (g.) (g.) (g.) (g.) (minutes) hardnessstructure I 2.9 0 1.5 0.3 3 23 Yes. I 2.3 0.6 1.5 0.3 6 13 Yes. I 1.71.2 1.5 0.3 7 0 Yes. I 1.2 1.7 1.5 0 3. 9 0 Yes. I 0.5 2.3 1.5 0.3 No. I0 2.9 1.5 0.3 No.

l Polyene prepolymer I from Example 8. 3 Q43=pentaerythn'tol tetrakis(fl-mcrcaptopropionate) commercially available from Carlisle ChemicalCo. 3 E23=ethylene glycol bis(B-mereaptopropionate).

4 No cure.

EXAMPLES 81-86 l 30 g. polyene preploymer I from Example 8.

2 Q-43=pentaerythrltol tetrakis (fl-mercaptopropionate) commerciallyavailable from Carlisle Chemical Co.

3 N o cure in 72 hours.

product. The example containing Dalpac FG cured to a solid polymerproduct after 12 days whereas the sample containing Santonox requiredmore than 2 weeks before a solid self-supporting, cured polymericproduct resulted.

The polyenes used in the instant invention may be used as blends ormixtures of monoenes or polyenes having the same or differentfunctionalities so long as the average functionality of the blend ormixture is at least 2. Similarly, the polythiols used herein maybe usedas blends or mixtures of monothiols or polythiols having the same ordifferent functionalities as long as the average functionality of theblend or mixture is at least 2.

31 The above formulations were briefly admixed for homogeneity andthereafter air cured indoors. Formulation I cured in approximately 6hours to an elastomeric sealant whereas Formulation II cured in two daysto an elastomeric sealant.

Example 88 10 grams of Prepolymer D were charged to a 2 oz. glass jaralong with 0.7 g. of ethylene glycol bis(mercaptopropionate), 2.2 g.pentaerythritol tetrakis(/3-mercaptopropionate), 0.5 g. 10% benzoylperoxide in benzene and 0.1 g. N,N-dimethylaniline. The reactants werebriefly stirred and then placed between two pieces of aluminum foil,each of 5 mil thickness. The aluminum foil was pressed together by handto insure good adhesion. After 1 hour an attempt was made to pull thealuminum foil apart. The aluminum foil tore before the adhesive wasdestroyed.

Example 89 50 grams of Prepolymer H along with 5.0 g. of pentaerythritoltetrakis(B-mercaptopropionate), 2.5 g. of a benzoyl peroxide in benzeneand 0.5 g. N,N-dimethylaniline were stirred together briefly in a glassjar and then poured into an aluminum mold in the shape of a shallowdish. The mold was allowed to set for 5 hours after which time the moldwas torn away from the molded article which set to a solid in the exactshape of the mold.

Example 90 0.005 mole of Prepolyrner E from Example 5 was charged to a 2oz. glass jar along with 0.0033 mole of trimethylolpropanetris(fi-mercaptopropionate), 0.2 g. benzoyl peroxide and 0.5 g.dimethylaniline. The reactants were stirred briefly and then coated ontoa piece of 17 pt. clay coated paper by means of a No. 10 rod. The paperwas then set aside at ambient conditions. After 10 minutes a clear,solid coating resulted on the paper. The same technique was usedsuccessfully to coat cellophane, aluminum foil, steel plate stock, Mylarpolyester film, plywood, and a concrete block of the type used inbuilding construction.

taerythritol tetrakis(fimercaptopropionate) and acetophenone byirradiation with ultraviolet light also had a Gardner color of lessthan 1. However, after hours in the F adeometer the Gardner color roseto 13.

Example 92 5.2 grams of decaglycerol dioleate (Drew Chemical Corp.) and2.0 grams of ethylene bis(;3-mercaptopropionate) were dissolved inethanol in an aluminum tray. 0.04 gram of benzoyl peroxide and 0.1 gramdimethylaniline were added to the mixture and the mixture was set asideunder ambient conditions. After 3 days the product had not solidified toa crosslinked network.

Example 93 94.5 grams of dimer acid commercially available from EmeryIndustries, Inc., under the trade name Empol 1010 and 103.5 grams ofallyl alcohol were admixed in benzene in a 2-ncck flask. The reactionwas heated gently for 19 hours at 80 C. at which time it was determinedby titration that less than 6% of the carboxyl group content wasunreacted. The reaction was discontinued and the reactants were washedwith water. The thus-formed emulsion was salted out thoroughly, thebenzene layer was separated and dried to remove residual moisture. Thebenzene was distilled off in vacuum to obtain the diallyl ester of dimeracid.

The diallyl ester of the dimer acid product (30 grams) was admixed withQ-43 in a 1:1 mole ratio along with 0.15 gram benzoyl peroxide and 0.3gram dimethylaniline in an aluminum tray. After 30 minutes a cured solidproduct resulted.

The curing example was repeated except that the mole ratio of thediallyl ester of dimer acid to Q-43 was 2:1. The cured product washarder than the product obtained under the 1:1 mole ratio of diallylester to Q43.

14 grams of dimer acid, 6 grams of pentaerythritoltetrakis(B-mercaptopropionate), 0.07 gram benzoyl peroxide and 0.15 gramdimethylaniline were mixed in an aluminum tray. The mixture was setaside under ambient conditions. After 22 hours the product had notsolidified to a. crosslinked network.

EXAMPLES 94-551 Polyene Chemical free radical generating Polyml Sourceof polyene reagent 1 thiol 3 '3 l,2,4-tiivinylcyclohcx ane 1,5-hcxadieneDiallyl terephthalat Diallyl oxalate Diallyl1,4-cyclohexanediearboxylate 99. Tetraallyl orthosilicate 100-. Diallyldiphenylsilane 101. Diallyl allyl phosphonate Diallyl phenyl phosphite.N,N-diallylfonnamide N,N,N,N-tetraallylmethylene aim Tri allyl cyanuratcTriallyl phosphate Diallyl carbonate N,N-diallyl piperazine Allyldiclycol carbonate.

4-vinyl-1-cyclohexene Dicthyleneglycol divinyl ether (.9 mole), diallylamine (.1 mole) Aldrich Chemical 00., Inc...

Benzoyl peroxidc-. Q-43 do.. Q-4

Monomer-Polymer Labs, Inc Aldrich Chemical Co. Inc Chemicals ProcurementLab. In

..do--..--- ..-d CR-39 from PPG Ind. Inc ..do.-

1 Concentration of dimethylaniline curing rate accelerator varied from1.0 to 3.0 parts/100 parts curable composition; benzoyl peroxide reagentconcentration was 0.2 to 0.5 part/100 parts of curable composition. Curethrough times ranged from 3 minutes to 15 minutes.

2 Q-43 is pentaerythn'tol tetrakis (dmercaptopropionate; P-33 istrimethylolpropane tris B-mercaptopropionate). The polythiol is used inthe theoretical equivalent amount based on the polyene used.

Example 91 Examples 112-120 Example 65 was repeated except that the .02mole of of diallyl amine was replaced by 0.02 mole of the polyenes fromExamples 24, 25, 27, 28, 30, 31, 32, 39 and 40, respectively In eachinstance a solid cured product was obtained in less than 20 minutesafter mixing was completed.

Example 121 916 grams (0.46 mole) of a commercially available liquidpolymeric diisocyanate sold under the trade name ene-2,4-diisocyanateand allyl alcohol, cured with pen- Adiprene L- by E. I. du Pont deNemours & Co.

were charged to a dry flask maintained under a nitrogen atmosphere andequipped with a condenser, stirrer, thermometer and gas inlet andoutlet. 197 grams (0.92 mole) of the diallyl ether of trimethylolpropanewere charged to the vessel along with 0.56 g. dibutyl tin dilauratecatalyst. The flask and contents were heated with stirring for 30minutes at 50 C. to yield a polytetraene of about 2400 M.W.

To the tetraene were added 230 grams pentaerythritoltetrakis(,8-mercaptopropionate), 1.2 grams dilaurylthio-dipropionate,136 grams of dioctyl phthalate, 1.2 grams Plastanox 2246 (hinderedphenol antioxidant sold by American Cyanamid Co.), 6.7 grams benzoylperoxide and 14 grams dimethylaniline. An aliquot of this chemicallycurable liquid composition was cast on a glass plate in a layer 40 milsthick. The layer skin cured to a solid through the entire thickness inless than 3 minutes, or at a liquid-to-solid conversion rate of over 13mils/minute. The solid rubbery product had a Shore A hardness of 60, atensile strength of 150 p.s.i. and an elongation at failure of 25percent.

Example 122 An 80/20 mixture of tolylene 2,4-diisocyanate and tolylene2,6-diisocyanate (1 mole) was reacted with allyl alcohol (2 moles) underthe conditions used for the similar synthesis described in Example 116.The resulting diene (3 moles) was mixed with 2.1 moles of the tris(3-mercaptopropyl) ether of tris(2-hydroxyethyl) isocyanurate, 0.5 partbenzoyl peroxide and 1.0 part dimethylaniline per 100 parts of curablecomposition.

100 grams of the above curable composition 'were placed in a layer 500mils deep in a small aluminum mold and set aside at ambient conditions.After 5 minutes the liquid composition was cured to a crosslinked solidhaving a Shore A hardness greater than 20. The conversion from liquid tosolid occurred at a rate of over 100 mils/minute.

The solid cured polythioether polymer products resulting from theinstant invention have many and varied uses. Examples of some usesinclude but are not limited to adhesives; caulks; elastomeric sealants;coatings, encapsulating or potting compounds; liquid castableelastomers; thermoset resins; impregnants for fabric, cloth, fibrouswebs and other porous substrates; laminating adhesives and coatings;mastics; glazing compounds; fiberglass reinforced composites; sizing orsurface finishing agents; filleting compounds; cure in place gasketingcompounds; rocket fuel binders; foamable thermosetting resins orelastomers; molded articles such as gaskets, diaphragms, balloons,automobile tires, etc.

The molecular weight of the polyenes of the present invention may bemeasured by various conventional methods, including solution viscosity,osmotic pressure and gel permeation chromatography. Additionally, themolecular weight may be calculated from the known mo lecular weight ofthe reactants.

The viscosity of the polyenes and polythiols may be measured on aBrookfield Viscometer at 30 or 70 C. in accord with the instructionstherefor.

The components to be cured may be prepared as either single-packaged ormulti-packaged liquid polymer systems which may be cured to solidpolythioether elastomers without liberating gaseous by-products whichcause bubbles and voids in the vulcanizate. Thus, there is providedcurable liquid polymer systems composed of polyenes and polythiols inwhich the components individually are storage stable and which are notsensitive to or deteriorated by traces of moisture or oxygen containinggas such as may be encountered during normal storage or handlingprocedures. Solid resinous or elastomeric products may be prepared fromfiowable liquids in a system in which the rate of curing may beinhibited or retarded by the use of chemical inhibitors, antioxidants,inert atmospheres and the like. The cured product may be characterizedas in the thermally and oxidatively stable state since there is noreactive carbon-to-carbon unsaturation in the main backbone chain.

As used herein the term polyene and the term polyne refers to single orcomplex species of alkenes or alkynes having a multiplicity of terminalreactive carbon-to-carbon unsaturated functional groups per averagemolecule. For example, a diene is a polyene that has two reactivecarbon-to-carbon double bonds per average molecule, while a diyne is apolyne that contains in its structure two reactive carbon-to-carbontriple bonds per average molecule. Combinations of reactive double bondsand reactive triple bonds within the same molecule are also possiblesuch as for monovinylacetylene which is a polyeneyne under thisdefinition. For purposes of brevity all these classes of compounds arereferred to hereafter as polyenes.

In defining the position of the reactive functional carbon-to-carbonunsaturation, the term terminal is intended to mean that functionalunsaturation is at an end of the main chain in the molecule; whereas bynear terminal is intended to mean that the functional unsaturation isnot more than 10 carbon atoms and typically less than 8 carbon atomsfrom an end of the main chain in the molecule. The term pendant meansthat the reactive carbon-to-carbon unsaturation is located terminal ornearterminal in a branch of the main chain as contrasted to a positionat or near the ends of the main chain. For purposes of brevity all ofthese positions are referred to herein generally as terminalunsaturation.

Functionality as used herein refers to the average number of ene orthiol groups per molecule in the polyene or polythiol, respectively. Forexample a triene is a polyene with an average of three reactivecarbon-to-carbon unsaturated groups per molecule and thus has afunctionality (f) of three. A dithiol is a polythiol with an average oftwo thiol groups per molecule and thus has a functionality (f) of two.

It is to be understood that the functionality of the polyene and thepolythiol component is commonly expressed in whole numbers although inpractice the actual functionality may be fractional. For example, apolyene component having a nominal functionality of 2 (from theoreticalconsiderations alone) may in fact have an effective functionality ofsomewhat less than 2. In an attempted synthesis of a diene from a glycolin which the reaction proceeds to 100% of the theoretical value forcomplete reaction, the functionality (assuming 100% pure startingmaterials) would be 2.0. If however, the reaction were carried to onlyof theory for complete reaction, about 10% of the molecules presentwould have only one ene functional group, and there may be a trace ofmaterial that would have no ene functional groups at all. Approximately90% of the molecules, however, would have the desired diene structureand the product as a whole then would have an actual functionality of1.9. Such a product is useful in the instant invention and is referredto herein as having a functionality of 2.

The term reactive unsaturated carbon-to-carbon groups means groups whichwill react under proper conditions as set forth herein with thiol groupsto yield the thioether as contrasted to the term unreactivecarbon-to-carbon unsaturation which means groups found in aromaticnuclei (cyclic structures exemplified by benzene, pyridine, anthracene,and the like) which do not under the same conditions react with thiolsto give thioether linkages.

Highly water-sensitive groups are intended to include, for example,isocyanate, acylhalide such as acylchloride, anhydride and the likewhich readily react with water, alcohols, ammonia, amines and the like.

Odorless has been used herein to mean the substantial absence of thewell-known olfensive and sometimes obnoxious odors that arecharacteristic of hydrogen sulfide and the derivative family ofcompounds known as mercaptans.

The term non-yellowing means the substantial resistance during prolongedexposure to actinic radiation such as exposure in sunlight, to unsightlyor uncontrollable discoloration.

It is understood that the foregoing detailed description is given merelyby way of illustration and that many variations may be made thereinwithout departing from the spirit of this invention.

What is claimed is:

1. A chemically curable composition useful for obtaining an essentiallyodorless, solid polythioether, said curable composition consistingessentially of:

(A) a terminally unsaturated polyene component which comprises theformula:

wherein m is an integer of at least 2; wherein X is where R is a radicalselected from the group consisting of hydrogen, fluorine, chlorine,furyl, thienyl, pyridyl, phenyl and substituted phenyl, benzyl andsubstituted benzyl, alkyl and substituted alkyl, alkoxy and substitutedalkoxy, cycloalkyl and substituted cycloalkyl; said substituents on saidsubstituted members selected from the group consisting of nitro, chloro,fluoro, acetoxy, acetamide, phenyl, benzyl, alkyl, alkoxy andcycloalkyl; said alkyl and alkoxy having from 1 to 9 carbon atoms andsaid cycloalkyl having from 3 to 8 carbon atoms; wherein [A] is free ofreactive carbon-to-carbon unsaturation; free of highly water-sensitivemembers; and is a polyvalent chemically compatible member of the groupconsisting of carbonate, carboxylate, carbonyl, ether, silane, silicate,phosphonate, phosphite, phosphate, alkyl and substituted alkyl,cycloalkyl and substituted cycloalkyl, aryl and substituted aryl,urethane and substituted urethane, urea and substituted urea, amine andsubstituted amine, amide and substituted amide, hydroyl, heterocycliccarbon containing radical, and mixtures thereof; said substituents onsaid members substituted being defined above, said component having amoleclar weight in the range from about 64 to 20,000; and a viscosity inthe range from essentially to 20 million centipoises at 70 C.; and (B) apolythiol components having a molecular Weight in the range from about50 to about 20,000 of the general formula:

wherein R is a polyvalent organic moiety free from reactivecarbon-to-carbon unsaturation and n is at least 2, the sum of m and nbeing greater than 4, with the ene/thiol mole ratio being selected so asto provide a cross-linked solid, self-supporting cured product, and (C)a chemical free radical generating reagent. 2. The composition of claim1 wherein [A] has the formula:

RJCHjL mil...

a and b are integers greater than 1;

R is a member of the group consisting of hydrogen and alkyl;

R is a member of the group consisting of hydrogen,

and saturated alkyl;

R is a divalent derivative of the group consisting of phenyl, benzyl,alkyl, cycloalkyl, substituted phenyl, substituted benzyl, substitutedalkyl and substituted cycloalkyl,

said alkyl, cycloalkyl and substituents on members substituted beingdefined as in claim 1.

3. The composition of claim 1 wherein the mole ratio of ene to thiol isfrom about 0.5/1 to about 2/1.

4. The composition of claim 1 wherein the mole ratio of ene to thiol isfrom about 0.75/1 to about 1.5/1.

5. The composition of claim 1 wherein the chemical free radicalgenerating reagent is selected from the group consisting of molecularoxygen; organic hydroperoxides and peroxides; blends of organichydroperoxides and per oxides with tertiary amines; blends of organichydroperoxides and peroxides with transition metal salts; and blends oforganic hydroperoxides and peroxides with ter tiary amines andtransition metal salts.

6. A process of forming essentially odorless solid polythioether whichcomprises (I) Admixing:

(A) a terminally unsaturated polyene component which comprises theformula:

wherein l-( M wherein m is an integer of at least 2; wherein X is R RS=-R where R is a radical selected from the group consisting ofhydrogen, fluorine, chlorine, furyl, thienyl, pyridyl, phenyl andsubstituted phenyl, benzyl and substituted benzyl, alkyl and substitutedalkyl, alkoxy and substituted alkoxy, cycloalkyl and substitutedcycloalkyl; said substituents on said substituted members selected fromthe group consisting of nitro, chloro, fluoro, acetoxy, acetamide,phenyl, benzyl, alkyl, alkoxy and cycloalkyl; said alkyl and alkoxyhaving from 1 to 9 carbon atoms and said cycloalkyl having from 3 to 8carbon atoms;

wherein [A] is free of reactive carbon-to-carbon unsaturation; free ofhighly Water-sensitive members; and is a polyvalent chemicallycompatible member of the group consisting of carbonate, carboxylate,carbonyl, ether, silane, silicate, phosphonate, phosphite, phosphate,alkyl and substituted alkyl, cycloalkyl and substituted cycloalkyl, aryland substituted aryl, urethane and substituted urethane, urea andsubstituted urea, amine and substituted amine, amide and substitutedamide, hydroxyl, heterocyclic carbon containing radical, and mixturesthereof; said substituents on said members substituted being definedabove,

said component having a molecular weight in the range from about 64 to20,000; and

a viscosity in the range from essentially to million centipoises at 70C.; and (B) a polythiol component having a molecular weight in the rangefrom about 50 to about 20,- 000 of the general formula:

Rs-(SH)n wherein R is a polyvalent organic moiety free from reactivecarbon-to-carbon unsaturation and n is at least 2, the sum of m and nbeing greater than 4, with the ene/thiol mole ratio being selected so asto provide a cross-linked solid, selfsupporting cured product, and (C) achemical free radical generating reagent.

7. An article comprising the composition of claim 6 as a coating on asubstrate.

8. An article comprising the composition of claim 6 as an adhesivebetween two substrates.

9. An article comprising the composition of claim 6 as an elastomericsealant.

10. A shaped, molded article cast from the composition of claim 6.

11. The process of claim 6 wherein the chemical free radical generatingreagent is selected from the group consisting of molecular oxygen;organic hydroperoxides and peroxides; blends of organic hydroperoxidesand peroxides with tertiary amines; blends of organic hydroperoxides andperoxides with transition metal salts; and blends of organichydroperoxides and peroxides with tertiary amines and transition metalsalts.

TAT/T 38 12. The composition of claim 1 wherein the polyene has theformula:

where the sum of x+y+z in each chain segment is at least 1; and n is aninteger of 0 or greater.

13. The composition of claim 1 wherein the polyene has the formula:

HIHz

where n is an integer of 0 or greater.

14. The composition of claim 1 wherein the polyene has the formula:

where n is an integer of 0 or greater.

References Cited UNITED STATES PATENTS 3,405,181 10/1968 Gourdon 260793,278,352 10/ 1966 Erickson 26079 3,371,072 2/1968 Signouret et a1.26079 3,338,810 8/1967 Warner 26079 3,412,049 11/ 1968 Gmitter 2602.5 R2,921,006 1/1960 Schmitz et a1 204159.l5

MURRAY TILLMAN, Primary Examiner R. B. TURER, Assistant Examiner U.S.Cl. X.R.

117-9331, 132 B, 132 R, 138.8 15, 148, 204 159.14, 159.15, 159.18,159.23, 159.24; 2602.5 A, 2.5 R, 17.4 R, 41 AB, 63 UY, 77.5 BB, 77.5 CR,77.5 MA, 77.5 AM, 79.5 B, 79.5 R, 79.5 NV, 823, 860, 874; 266- 41 A, 41B, 41 R

